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Amyotrophic lateral sclerosis (ALS) progressively impairs motor neurons, leading to muscle weakness and loss of voluntary muscle control. This study compared the effects of SOD1 mutation on masticatory and limb muscles from disease onset to death in ALS model mice. Notably, limb muscles begin to atrophy soon after ALS-like phenotype appear, whereas masticatory muscles maintain their volume and function in later stages. Our analysis showed that, unlike limb muscles, masticatory muscles retain their normal structure and cell makeup throughout most of the disease course. We found an increase in the number of muscle satellite cells (SCs), which are essential for muscle repair, in masticatory muscles. In addition, we observed no reduction in the number of muscle nuclei and no muscle fibre-type switching in masticatory muscles. This indicates that masticatory muscles have a higher resistance to ALS-related damage than limb muscles, likely because of differences in cell composition and repair mechanisms. Understanding why masticatory muscles are less affected by ALS could lead to the development of new treatments. This study highlights the importance of studying different muscle groups in ALS to clarify disease aetiology and mechanisms.

BACKGROUND: Acute exercise tends to cause skeletal muscle tissue damage and lipid metabolism disorders in vivo, but the mechanism by which acute exercise combined with electroacupuncture modulates metabolic and autophagic pathways in vivo is unclear. OBJECTIVE: To observe the changes in metabolic enzymes and autophagy levels in skeletal muscle of rats subjected to acute exercise by electroacupuncture at the acupoints of “Zusanli” and “Huantiao.” METHODS: Fifty male Sprague-Dawley rats were randomly divided into three groups: quiet control group (n=10), model group (n=20), and reverse electroacupuncture group (n=20). The latter two groups were set up with two time points, i.e. immediate and 3 hours after exercise groups (n=10 per time point). The model group and the reverse electroacupuncture group underwent acute exercise training after adaptive treadmill training. The rats in the reverse electroacupuncture group underwent electroacupuncture treatment (parameters: electroacupuncture on both sides of the rats at the acupoints of “Zusanli” and “Huantiao,” continuous wave, frequency of 2 Hz, intensity of 2 mA, leaving the needle in the body for 30 minutes, once a day for 7 consecutive days) before treadmill training. Bilateral gastrocnemius muscle tissues were taken under anesthesia immediately after exercise and 3 hours after exercise, and hematoxylineosin staining was used to observe the histopathological changes of rat skeletal muscle. ELISA kit was used to detect the activities of hepatic lipase, fatty acid synthase, hormone-sensitive lipase, and carnitine palmitoyltransferase 1 in rat skeletal muscle tissues. Immunohistochemistry and western blot were used to detect the changes in the expression of autophagy genes. RESULTS AND CONCLUSION: After hematoxylin-eosin staining, the arrangement of gastrocnemius muscle fibers in the model group was disturbed, swollen and ruptured immediately after exercise and 3 hours after exercise. In the reverse electroacupuncture group, gastrocnemius muscle fibers were tightly arranged and the number of swollen and ruptured cells was greatly reduced immediately after exercise and 3 hours after exercise, and there was no significant difference when compared with the quiet control group. Compared with the quiet control group, the activities of hepatic lipase and fatty acid synthase were lower while the activities of lipoprotein lipase, hormone-sensitive lipase, and carnitine palmitoyltransferase 1 were higher in the model group and the reverse electroacupuncture group 3 hours after exercise (P < 0.05 or P < 0.01). Compared with the model group, the activities of lipoprotein lipase and carnitine palmitoyltransferase 1 were higher in the reverse electroacupuncture group immediately after exercise (P < 0.05), while the activity of lipoprotein lipase was higher and the activity of hormone-sensitive lipase was lower in the reverse electroacupuncture group 3 hours after exercise (P < 0.01). Immunohistochemical results showed that compared with the quiet control group, the expression of P62, autophagy-related gene 5 and autophagy-related gene 7 was higher in the model group immediately and 3 hours after exercise, as well as in the reverse electroacupuncture group immediately after exercise (P < 0.05 or P < 0.01); compared with the model group, the expression of P62 and autophagy-related gene 7 was lower in the reverse electroacupuncture group immediately and 3 hours after exercise (P < 0.05). Western blot results showed that the protein expression of P62 and autophagy-related gene 7 in the reverse electroacupuncture group was lower than that in the model group immediately after exercise (P < 0.05); the protein expression of Parkin in the model group was higher than that in the quiet control group immediately and 3 hours after exercise (P < 0.05); and the protein expression of Parkin in the reverse electroacupuncture group was lower than that in the model group immediately and 3 hours after exercise (P < 0.05). To conclude, acute exercise induces disorders, swelling and rupture of gastrocnemius muscle fibers in rats and electroacupuncture on both sides of the acupoints of “Zusanli” and “Huantiao” can improve the level of lipid metabolism and regulate autophagy cells in rat skeletal muscle, preventing the disorders of lipid metabolism and damage of gastrocnemius muscle tissues caused by acute exercise. The mechanism may be closely related to the regulation of autophagy-related factor P62, autophagy-related gene 5, autophagyrelated gene 7, and Parkin protein expression to promote the occurrence of autophagy or regulate the autophagy pathway in rat skeletal muscle cells. [ABSTRACT FROM AUTHOR]

Background: Exercise training positively modulates myokine secretion and improves glucose metabolism. Herein, we analyzed the effect of moderate-intensity training, detraining, and Protocatechuic Acid (PCA) supplementation on myokine secretions and regulation of insulin-signaling pathways. Methods: A five-arm study was conducted on 47 healthy male Wistar rats, trained at a moderate intensity level for four weeks (T0-T4). Animals were randomly classified into groups according to PCA supplementation and exercise durations: four weeks of Aerobic Training with or without PCA (AT4, AT4-PCA), eight weeks of Aerobic Training with or without PCA (AT8, AT8-PCA), and PCA Vehicle Control (VC). The animals were followed up until week 12 (T12). We decapitated six rats at T0 and T4, four rats per group at T8, and three rats per group at T12. Myokines (IGF-1, IL-6, FGF-21, myostatin, and irisin) were analyzed with ELISA. Western blot analysis measured protein expression of insulin-signaling pathways and GLUT-4 in the gastrocnemius muscle. Results: The IL-6 levels increased significantly (p < 0.01) with 8-week training in AT8 by 34% and AT8-PCA by 32%, compared to groups trained for only 4 weeks (AT4 and AT4-PCA). Similarly, the PI3K, and GLUT-4 expression improved in AT8 and AT8-PCA at T8. Training for 4 weeks improved IGF-1 levels, but a further 14% improvement was observed with 8-week training in AT8 at T8. Myostatin level significantly dropped by 27% even with 4-week training (p < 0.001). However, detraining increased the myostatin levels in all groups, but in AT8-PCA with PCA dose, myostatin reduced by 11% compared to AT8 at T12. PCA supplementation reduced the FGF-21 levels by 54% during detraining at T12 in AT8-PCA compared to AT8. However, the irisin level did not change markedly in any group. Conclusions: Physical training (with and without PCA) modulates myokine production and improves glucose metabolism, but the benefits are lost after detraining. [ABSTRACT FROM AUTHOR]

BACKGROUND: Lijin manipulation can reduce fibrosis scar hyperplasia and promote skeletal muscle repair. However, improper activation of the Wnt/β-catenin signaling pathway can aggravate the fibrosis of injured skeletal muscle and adversely affect the repair process of skeletal muscle. To study the regulatory effect of Lijin manipulation on the Wnt/β-catenin signaling pathway is conducive to elucidate the related mechanisms of Lijin manipulation in reducing fibrosis scar hyperplasia and promoting skeletal muscle injury repair. OBJECTIVE: To explore the mechanism of Lijin manipulation in promoting the repair of skeletal muscle injury in rabbits. METHODS: Forty-five healthy adult Japanese white rabbits were randomly divided into blank group, model group and Lijin group with 15 rabbits in each group. Gastrocnemius muscle percussion modeling was performed in both model group and Lijin group. Lijin manipulation was performed in the Lijin group on the 3rd day after modeling, once a day, 15 minutes once. Five animals in each group were selected and killed on the 7th, 14th and 21st days after modeling. The general morphological structure of gastrocnemius was observed by hematoxylin-eosin staining and the content of collagen fiber was observed by Masson staining. Western blot was used to detect the protein expression of Wnt3a, β-catenin, GSK3β, p-GSK3β, TCF, type I collagen and type III collagen in gastrocnemius muscle, and RT-PCR was used to detect the mRNA expression of Wnt3a, β-catenin and TCF. The expression of β-catenin was detected by immunofluorescence, and the expression of type I collagen and type III collagen was detected by immunohistochemistry. RESULTS AND CONCLUSION: The results of hematoxylin-eosin staining and Masson staining showed that compared with the model group, inflammatory cell infiltration and collagen fiber amount decreased in the Lijin group (P < 0.001), and muscle fibers gradually healed. Western blot results showed that compared with the model group, the protein expression levels of Wnt3a, β-catenin, TCF, type I collagen and type III collagen were significantly decreased in the Lijin group at all observation time points (P < 0.05), while the ratio of P-GSK3β/GSK3β was significantly increased in the Lijin group at all observation time points compared with the model group (P < 0.05). RT-PCR results showed that compared with the model group, the mRNA expression levels of Wnt3a, β-catenin and TCF were significantly decreased in the Lijin group at all observation time points (P < 0.001). Immunofluorescence results showed that compared with the model group, the fluorescence intensity of β-catenin expression in the Lijin group was significantly decreased at each observation time point and gradually became similar to that in the blank group (P < 0.001). Immunohistochemical results showed that the expression levels of type I collagen and type III collagen in the Lijin group were significantly lower than those in the model group (P < 0.01). To conclude, Lijin manipulation could inhibit the abnormal activation of the Wnt/β-catenin signaling pathway, reduce fibrotic scar hyperplasia, and promote the repair of injured skeletal muscle. [ABSTRACT FROM AUTHOR]

Abstract Amyotrophic lateral sclerosis (ALS) progressively impairs motor neurons, leading to muscle weakness and loss of voluntary muscle control. This study compared the effects of SOD1 mutation on masticatory and limb muscles from disease onset to death in ALS model mice. Notably, limb muscles begin to atrophy soon after ALS-like phenotype appear, whereas masticatory muscles maintain their volume and function in later stages. Our analysis showed that, unlike limb muscles, masticatory muscles retain their normal structure and cell makeup throughout most of the disease course. We found an increase in the number of muscle satellite cells (SCs), which are essential for muscle repair, in masticatory muscles. In addition, we observed no reduction in the number of muscle nuclei and no muscle fibre-type switching in masticatory muscles. This indicates that masticatory muscles have a higher resistance to ALS-related damage than limb muscles, likely because of differences in cell composition and repair mechanisms. Understanding why masticatory muscles are less affected by ALS could lead to the development of new treatments. This study highlights the importance of studying different muscle groups in ALS to clarify disease aetiology and mechanisms.

It has been reported that glyphosate, one of the most common herbicides used in agriculture, impairs locomotion and cognition. Glyphosate has a variable half-life in soil up to biotic and/or abiotic factors transform the molecule in metabolites such as the aminomethylphosphonic acid (AMPA) that has a longer half-life. In this study, female Sprague Dawley rats were acutely exposed to different doses of glyphosate or AMPA (i.e. 10, 56 or 100 mg/kg) and, subsequently, the acetylcholinesterase (AChE) activity was measured in the hippocampus, prefrontal cortex (PFC) and the gastrocnemius muscle. Both glyphosate and AMPA produced a similar decrease in the AChE activity in all the tissues tested. These results suggest that interference with normal cholinergic neurotransmission may be one of the mechanisms involved in glyphosate-induced motor alterations in rats. Moreover, our results highlight the biological importance of AMPA as a molecule with anticholinesterase action in brain and skeletal muscle. To our knowledge, this is the first report showing in vivo that AMPA, the major metabolite of glyphosate, behaves as an organophosphate. [ABSTRACT FROM AUTHOR]

The popliteal fossa presents an extensive diamond-shaped topographical element on the posterior aspect of the knee. With the use of classical anatomical dissection, digital image analysis of NIS Elements AR 3.0, and statistics, we morphometrically analysed the size of the popliteal fossa in human foetuses aged 17-29 weeks of gestation. Morphometric parameters of the popliteal fossa increased logarithmically with foetal age: y = -44.421 + 24.301 × ln (age) for length of superomedial boundary, y = -41.379 + 22.777 × ln (age) for length of superolateral boundary, y = -39.019 + 20.981 × ln (age) for inferomedial boundary, y = -37.547 + 20.319 × ln (age), for length of inferolateral boundary, y = -28.915 + + 15.822 × ln (age) for transverse diameter, y = -69.790 + 38.73 × ln (age) for vertical diameter and y = -485.631 + 240.844 × ln (age) for projection surface area. Out of the 4 angles of the popliteal fossa the medial one was greatest, the inferior one the smallest, while the lateral one was somewhat smaller than the medial one and approximately 3 times greater than the superior one, with no difference with foetal age. In terms of morphometric parameters, the popliteal fossa in the human foetus displays neither male-female nor right-left differences. In the popliteal fossa, growth patterns of its 4 boundaries, vertical and transverse diameters, and projection surface area all follow natural logarithmic functions. All the morphometric data are considered age-specific reference intervals, which may be conducive in the diagnostics of congenital abnormalities in the human foetus. [ABSTRACT FROM AUTHOR]

Purpose: The gastrocnemius venous system presents different anatomical variants. There have been described four locations of myofascial trigger points (MTrPs) in this muscle. However, no studies have analyzed the coincidence between vessels and MTrPs present in the gastrocnemius. Therefore, the main objective was to study the anatomical variability of the venous system by ultrasound and its coincidence with the location of the MTrPs. Methods: A total of 100 lower limbs were studied. The gastrocnemius vessels were analyzed one by one by sector (medial, central, and lateral), quantifying the number of vessels, their distribution, and the coincidence with MTrPs. Results: All muscle heads showed at least one vessel per section. A large variability was observed, from one to eight vessels per muscle head, with the most frequent number being three in the gastrocnemius medialis and two in the gastrocnemius lateralis. In all cases, the location of the vessels coincided with the MTrPs. Conclusions: The proximal gastrocnemius venous pattern is very variable between subjects in number of vessels and distribution, which has made it impossible to define a "safe" approach window for invasive procedures without ultrasound guidance. The coincidence between the clinical location of MTrPs of the gastrocnemius and the presence of vessels is total. [ABSTRACT FROM AUTHOR]

Introduction Approximately 89% of all service members with amputations do not return to duty. Restoring intuitive neural control with somatosensory sensation is a key to improving the safety and efficacy of prosthetic locomotion. However, natural somatosensory feedback from lower-limb prostheses has not yet been incorporated into any commercial prostheses Materials and Methods We developed a neuroprosthesis with intuitive bidirectional control and somatosensation and evoking phase-dependent locomotor reflexes, we aspire to significantly improve the prosthetic rehabilitation and long-term functional outcomes of U.S. amputees. We implanted the skin and bone integrated pylon with peripheral neural interface pylon into the cat distal tibia, electromyographic electrodes into the residual gastrocnemius muscle, and nerve cuff electrodes on the distal tibial and sciatic nerves. Results. The bidirectional neural interface that was developed was integrated into the existing passive Free-Flow Foot and Ankle prosthesis, WillowWood, Mount Sterling, OH. The Free-Flow Foot was chosen because it had the highest Index of Anthropomorphicity among lower-limb prostheses and was the first anthropomorphic prosthesis brought to market. Conclusion. The cats walked on a treadmill with no cutaneous feedback from the foot in the control condition and with their residual distal tibial nerve stimulated during the stance phase of walking [ABSTRACT FROM AUTHOR]

The current cadaveric report aims to present a coexistence of two uncommon variants of the posterior leg compartment. The variations were detected, during classical dissection in an 84-year-old donated male cadaver. On the left lower limb, the gastrocnemius muscle was identified as having a third head that was attached to the lateral head. This variant is known as gastrocnemius tertius muscle and was bilaterally identified. The left-sided plantaris muscle had two distinct heads that fused into a common tendon that was inserted into the calcaneal tuberosity. Knowledge of these variants is important, due to their close relationship with the popliteal neurovascular bundle. Clinicians should be aware, to avoid pitfalls and take them into account in their differential diagnosis. [ABSTRACT FROM AUTHOR]

Although previous studies have reported fatty infiltration of the gastrocnemius–soleus complex, little is known about the volumetric distribution and patterns of fatty infiltration. The purpose of this anatomical study was to document and quantify the frequency, distribution, and pattern of fatty infiltration of the gastrocnemius–soleus complex. One hundred formalin‐embalmed specimens (mean age 78.1 ± 12.3 years; 48F/52M) were serially dissected to document the frequency, distribution, and pattern of fatty infiltration in the medial and lateral heads of gastrocnemius and soleus muscles. Fatty infiltration was found in 23% of specimens, 13 unilaterally (8F/5M) and 10 (5M/5F) bilaterally. The fatty infiltration process was observed to begin medially from the medial aspect of the medial head of gastrocnemius and medial margin of soleus and then progressed laterally throughout the medial head of gastrocnemius and the marginal, anterior, and posterior soleus. The lateral head of gastrocnemius remained primarily muscular in all specimens. Microscopically, the pattern of infiltration was demonstrated as intramuscular with intact aponeuroses, and septa. The remaining endo‐, peri‐, and epimysium preserved the overall contour of the gastrocnemius–soleus complex, even in cases of significant fatty replacement. Since the external contour of the calf is preserved, the presence of fatty infiltration may be underdiagnosed in the clinic without imaging. Myosteatosis is associated with gait and balance challenges in the elderly, which can impact quality of life and result in increased risk of falling. The findings of the study have implications in the rehabilitation management of elderly patients with sarcopenia and myosteatosis. [ABSTRACT FROM AUTHOR]

Previous studies have shown that oyster peptides (OPs) have antioxidant and anti-fatigue activities. This study aimed to investigate the effects of OPs on swimming endurance in mice and the underlying mechanisms. The mice were subjected to gavage with OPs and subjected to exercise training. After 14 days, various biochemical indicators in the blood and gastrocnemius muscle of mice were assessed, and real-time PCR was utilized to detect the level of signal pathway regulation by OPs in the gastrocnemius muscle. Molecular docking technology was employed to observe the potential active components in OPs that regulate signal pathways. In this study, OPs supplementation combined with and without exercise significantly extended swimming time compared to the sedentary group. OPs supplementation with exercise also increased glycogen levels and decreased blood urea nitrogen, lactate dehydrogenase, and lactic acid levels. Additionally, mice in the exercise with OPs group exhibited higher activities of antioxidant enzymes. OPs can upregulate metabolic regulatory factors such as AMP-activated protein kinase, peroxisome proliferator-activated receptor gamma coactivator-1 alpha, peroxisome proliferator-activated receptor delta, and glucose transporter 4, thereby increasing energy supply during exercise. Additionally, OPs enhances the expression of heme oxygenase 1 and superoxide dismutase 2, thereby reducing oxidative stress during physical activity. Molecular docking analyses revealed that peptides found in OPs formed hydrogen bonds with AMPK and HO-1, indicating that they can exert bioactivity by activating target proteins such as AMPK and HO-1. OPs supplementation improved energy reserves, modulated energy metabolism pathways, and coordinated antioxidative stress responses, ultimately enhancing swimming endurance. These findings suggest that OPs have the potential to improve exercise levels by promoting metabolism and improving energy utilization efficiency. [ABSTRACT FROM AUTHOR]

Running has become a popular national sport, increasing the risk of related injuries. Different striking patterns, such as forefoot (FFS) and rearfoot striking (RFS), contribute to varying injury types and influence muscle dynamics in the lower leg. This study examines the differences in force modes and muscle morphology of the gastrocnemius calf muscle under distinct striking patterns. A randomized controlled trial was conducted with twenty young female runners, ten typically striking on their forefoot and ten on their rearfoot, all without lower limb injuries in the past six months. Pre-run ultrasound measurements assessed the muscle thickness and pennation angle of the right gastrocnemius muscle, and electromyography (EMG) data were recorded post-treadmill run. An independent sample t-test compared the two groups. At the loading response stage, there was no significant difference in the root mean square (RMS) amplitude of the gastrocnemius muscle between the FFS and RFS groups, likely due to the delay between muscle activation and force generation. However, from mid-swing to late swing, the FFS group exhibited higher RMS amplitude, reflecting significantly greater muscle activation in the gastrocnemius muscle. This suggests increased muscle stiffness in the FFS group to cope with ground reaction forces, alongside higher activation and median frequency values in both the gastrocnemius medialis (GM) and gastrocnemius lateralis (GL), making the FFS group more prone to fatigue. Additionally, the gastrocnemius muscle thickness and fiber length in the RFS group were greater than in the FFS group. One limitation of this study is that inferring greater muscle explosive force solely based on muscle thickness and fiber length may be insufficient. Future research should incorporate biomechanical indicators, such as force plate testing, to better understand the relationship between muscle structure and function across different running styles.

Abstract Objective Type 2 diabetes mellitus (T2DM) is one of the high risk factors for sarcopenia. However, the pathogenesis of diabetic sarcopenia has not been fully elucidated. This study obtained transcriptome profiles of gastrocnemius muscle in normal and T2DM rats based on high-throughput sequencing technology, which may provide new ideas for exploring the pathogenesis of diabetic sarcopenia. Methods Twelve adult male Sprague-Dawley rats were randomly divided into Control group and T2DM group, and gastrocnemius muscle tissue was retained for transcriptome sequencing and real-time quantitative polymerase chain reaction (qRT-PCR) 6 months later. Screening differentially expressed genes (DEGs), Cluster analysis, gene ontology (GO) functional annotation analysis and Kyoto Encyclopedia of Genes and Gnomes (KEGG) functional annotation and enrichment analysis were performed for DEGs. Six DEGs related to apoptosis were selected for qTR-PCR verification. Results Transcriptomic analysis showed that there were 1016 DEGs between the gastrocnemius muscle of T2DM and normal rats, among which 665 DEGs were up-regulated and 351 DEGs were down-regulated. GO analysis showed that the extracellular matrix organization was the most enriched in biological processes, with 26 DEGs. The extracellular matrix with 35 DEGs was the most abundant cellular component. The extracellular matrix structural constituent, with 26 DEGs, was the most enriched in molecular functions. The highest number of DEGs enriched in biological processes, cellular components and molecular functions were positive regulation of transcription by RNA polymerase II, nucleus and metal ion binding, respectively. There were 78, 230 and 89 DEGs respectively. KEGG pathway enrichment analysis showed that ECM-receptor interaction, PI3K-Akt signaling pathway and TGF-β signaling pathway(p

Background: Exercise training positively modulates myokine secretion and improves glucose metabolism. Herein, we analyzed the effect of moderate-intensity training, detraining, and Protocatechuic Acid (PCA) supplementation on myokine secretions and regulation of insulin-signaling pathways. Methods: A five-arm study was conducted on 47 healthy male Wistar rats, trained at a moderate intensity level for four weeks (T0-T4). Animals were randomly classified into groups according to PCA supplementation and exercise durations: four weeks of Aerobic Training with or without PCA (AT4, AT4-PCA), eight weeks of Aerobic Training with or without PCA (AT8, AT8-PCA), and PCA Vehicle Control (VC). The animals were followed up until week 12 (T12). We decapitated six rats at T0 and T4, four rats per group at T8, and three rats per group at T12. Myokines (IGF-1, IL-6, FGF-21, myostatin, and irisin) were analyzed with ELISA. Western blot analysis measured protein expression of insulin-signaling pathways and GLUT-4 in the gastrocnemius muscle. Results: The IL-6 levels increased significantly (p < 0.01) with 8-week training in AT8 by 34% and AT8-PCA by 32%, compared to groups trained for only 4 weeks (AT4 and AT4-PCA). Similarly, the PI3K, and GLUT-4 expression improved in AT8 and AT8-PCA at T8. Training for 4 weeks improved IGF-1 levels, but a further 14% improvement was observed with 8-week training in AT8 at T8. Myostatin level significantly dropped by 27% even with 4-week training (p < 0.001). However, detraining increased the myostatin levels in all groups, but in AT8-PCA with PCA dose, myostatin reduced by 11% compared to AT8 at T12. PCA supplementation reduced the FGF-21 levels by 54% during detraining at T12 in AT8-PCA compared to AT8. However, the irisin level did not change markedly in any group. Conclusions: Physical training (with and without PCA) modulates myokine production and improves glucose metabolism, but the benefits are lost after detraining.

Objective: Type 2 diabetes mellitus (T2DM) is one of the high risk factors for sarcopenia. However, the pathogenesis of diabetic sarcopenia has not been fully elucidated. This study obtained transcriptome profiles of gastrocnemius muscle in normal and T2DM rats based on high-throughput sequencing technology, which may provide new ideas for exploring the pathogenesis of diabetic sarcopenia. Methods: Twelve adult male Sprague-Dawley rats were randomly divided into Control group and T2DM group, and gastrocnemius muscle tissue was retained for transcriptome sequencing and real-time quantitative polymerase chain reaction (qRT-PCR) 6 months later. Screening differentially expressed genes (DEGs), Cluster analysis, gene ontology (GO) functional annotation analysis and Kyoto Encyclopedia of Genes and Gnomes (KEGG) functional annotation and enrichment analysis were performed for DEGs. Six DEGs related to apoptosis were selected for qTR-PCR verification. Results: Transcriptomic analysis showed that there were 1016 DEGs between the gastrocnemius muscle of T2DM and normal rats, among which 665 DEGs were up-regulated and 351 DEGs were down-regulated. GO analysis showed that the extracellular matrix organization was the most enriched in biological processes, with 26 DEGs. The extracellular matrix with 35 DEGs was the most abundant cellular component. The extracellular matrix structural constituent, with 26 DEGs, was the most enriched in molecular functions. The highest number of DEGs enriched in biological processes, cellular components and molecular functions were positive regulation of transcription by RNA polymerase II, nucleus and metal ion binding, respectively. There were 78, 230 and 89 DEGs respectively. KEGG pathway enrichment analysis showed that ECM-receptor interaction, PI3K-Akt signaling pathway and TGF-β signaling pathway(p < 0.001) had higher enrichment degree and number of DEGs. qRT-PCR results showed that the fold change of Map3k14, Atf4, Pik3r1, Il3ra, Gadd45b and Bid were 1.95, 3.25, 2.97, 2.38, 0.43 and 3.6, respectively. The fold change of transcriptome sequencing were 3.45, 2.21, 2.59, 5.39, 0.49 and 2.78, respectively. The transcriptional trends obtained by qRT-PCR were consistent with those obtained by transcriptome sequencing. Conclusions: Transcriptomic analysis was used to obtain the "gene profiles" of gastrocnemius muscle of T2DM and normal rats. qRT-PCR verification showed that the genes related to apoptosis were differentially expressed. These DEGs and enrichment pathways may provide new ideas for exploring the pathogenesis of diabetic sarcopenia. [ABSTRACT FROM AUTHOR]

Sarcopenia is a musculoskeletal disease that reduces muscle mass and strength in older individuals. The study investigates the effects of azilsartan (AZL) on skeletal muscle loss in natural sarcopenic rats. Male Sprague-Dawley rats aged 4–6 months and 18–21 months were selected as young-matched control and natural-aged (sarcopenic) rats, respectively. Rats were allocated into young and old control (YC and OC) and young and old AZL treatment (YT and OT) groups, which received vehicles and AZL (8 mg/kg, orally) for 6 weeks. Rats were then sacrificed after muscle function analysis. Serum and gastrocnemius (GN) muscles were isolated for further endpoints. AZL significantly improved muscle grip strength and antioxidant levels in sarcopenic rats. AZL also restored the levels of insulin, testosterone, and muscle biomarkers such as myostatin and creatinine kinase in sarcopenic rats. Furthermore, AZL treatment improved the cellular and ultrastructure of GN muscle and prevented the shift of type II (glycolytic) myofibers to type I (oxidative) myofibers. The results showed that AZL intervention restored protein synthesis in natural sarcopenic rats by increasing p-Akt-1 and decreasing muscle RING-finger protein-1 and tumor necrosis factor alpha immunoexpressions. In conclusion, the present findings showed that AZL could be an effective intervention in treating age-related muscle impairments. [ABSTRACT FROM AUTHOR]

• FSO protects against dexamethasone-induced skeletal muscle atrophy by preventing loss and rupture of muscle fiber architecture. • FSO ameliorates liver enzymes SGOT and SGPT. • FSO shows protective effects via ameliorating antioxidant makers like SOD, GSH & CAT. • FSO also shows a protective effect on serological lipid profiles (HDL, LDL, triglycerides & total cholesterol) in dexamethasone-induced skeletal muscle atrophy in rat. The production of omega-3 fatty acids in the lipids of muscle tissue was boosted by flaxseed oil (Linum usitatissimum), which is well-described in the Ayurvedic system of medicine. In skeletal muscle disorders, atrophy is a major problem which arises due to cachexia, sarcopenia and immobilization. Nevertheless, despite significant efforts, few FDA-approved medications are available in the market to treat skeletal muscle atrophy. The current project was conceptualized to investigate the protective effects of flaxseed oil against dexamethasone-induced muscular atrophy in adult Sprague Dawley Rats. Marketed preparation of dexamethasone was used to induce muscle atrophy and flaxseed oil was administered orally after disease induction of 7 days till 28 days. Body weight and behavioural studies were carried out to assess muscle mass and glucose. Due to its high antioxidant and fatty acid Omega-3 content, flaxseed oil promotes significant improvements in diseased animals. Rats administered with flaxseed oil demonstrated great weight gain and a decreased blood sugar level. After three weeks-blood sugar levels, muscle mass, momentary changes in rats and HDL levels were all significantly higher in the dexamethasone alone treated control group animals. Flaxseed oil protects against the biochemical and histopathological changes caused due to dexamethasone toxicity. The findings of this study reveals that, flaxseed oil protects against dexamethasone induced skeletal muscle atrophy and protective effect may be due to flaxseed oil's antioxidant properties. However, further research is essential to prove the protective effects of flaxseed oil in some more studies mainly revealing its actions at cellular and molecular level. [ABSTRACT FROM AUTHOR]

Background: Although muscles and their tendons are not considered the most morphologically variable structures, they still manifest a substantial diversity of variants. The aim of this study is to increase awareness of some of the many possible variants found during ultrasound imaging of one lower limb compartment, the leg, that could potentially mislead clinicians and lead to misdiagnosis. Materials and methods: PubMed was used for a comprehensive literature search for morphological variations. Relevant papers were included, and citation tracking was used to identify further publications. Results: Several morphological variants of muscles of the leg have been described over many years, but this study shows that the occurrence of further variations in ultrasound imaging requires further investigations. Conclusions: The incidence of additional structures including muscles and tendons during ultrasound examination can cause confusion and lead to misinterpretation of images, misdiagnosis, and the introduction of unnecessary and inappropriate treatments. [ABSTRACT FROM AUTHOR]

Popliteal vein entrapment syndrome (PVES) is a rare subtype of popliteal entrapment syndrome that leads to symptoms of chronic venous stasis. We report a case of isolated PVES in a young patient associated with an accessory slip of the lateral head of the gastrocnemius muscle. The patient underwent resection of the anomalous muscle, and the symptoms were relieved postoperatively. PVES should be considered in young patients with unexplained symptoms or signs of venous stasis. Surgical resection of the causative lesion compressing the popliteal vein is indicated for selected patients.

Wen Wei,1,2,&ast; Chengwen Xie,3,&ast; Ronghua Cao,4,&ast; Yanwen Que,3 Xuejing Zhong,5 Zheyuan Chen,6 Fenyan Lv,6 Qianqian Kang,6 Ruiyu Lin,6 Baozhen Cao,7 Xiaomin Lai,7 Mei Tu1 1Department of Endocrinology, Fujian Longyan First Hospital, Longyan First Affiliated Hospital of Fujian Medical University, Longyan, 364000, People’s Republic of China; 2Department of Endocrinology, Zhujiang Hospital, Southern Medical University, Guangzhou, 510280, People’s Republic of China; 3Department of Ultrasonography, Fujian Longyan First Hospital, Longyan First Affiliated Hospital of Fujian Medical University, Longyan, 364000, People’s Republic of China; 4Department of Nuclear Medicine, Fujian Longyan First Hospital, Longyan First Affiliated Hospital of Fujian Medical University, Longyan, 364000, People’s Republic of China; 5Department of Science and Education, Fujian Longyan First Hospital, Longyan First Affiliated Hospital of Fujian Medical University, Longyan, 364000, People’s Republic of China; 6Department of Endocrinology, Fujian Longyan First Hospital, Fujian Medical University, Fuzhou, 350004, People’s Republic of China; 7Department of Pulmonary and Critical Care Medicine, Fujian Longyan First Hospital, Longyan First Affiliated Hospital of Fujian Medical University, Longyan, 364000, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Mei Tu, Department of Endocrinology, Fujian Longyan First Hospital, Longyan First Affiliated Hospital of Fujian Medical University, Longyan, 364000, People’s Republic of China, Tel +86 5972958989, Fax +86 5972292374, Email tm13859596628@163.comObjective: This study aims to examine the clinical significance of ultrasound evaluation of the gastrocnemius muscle (GM) in identifying sarcopenia in patients with type 2 diabetes (T2D).Methods: One hundred and fifty-three patients with T2D were included in this study. We measured the appendicular skeletal muscle mass index (ASMI), handgrip strength, and 6-meter walking speed. The US-derived muscle thickness (MT), cross-sectional area (CSA), and shear wave ultrasound elastography (SWE) of GM were also measured. We assessed the correlations between clinical indicators and US features. The model for screening sarcopenia was established using stepwise logistic regression. Stepwise linear regression was used to identify a set of variables that jointly estimated ASMI. The model’s ability to identify sarcopenia and low muscle mass was assessed by receiver operating characteristic (ROC) curve analysis.Results: The prevalence of sarcopenia in this study was 24.2%. The CSA, MT and SWE values of the patients with sarcopenia were lower than those of patients without sarcopenia (all p < 0.05). ASMI was positively correlated with CSA (r = 0.56, p < 0.001) and MT (r = 0.39, p < 0.001). Handgrip strength was positively correlated with CSA (r = 0.45, p < 0.001), MT (r = 0.25, p < 0.001), and SWE (r = 0.26, p = 0.002). A diagnostic model for sarcopenia was established with a sensitivity of 81.1%, specificity of 75.0%, and an area under the curve (AUC) of 0.800. The estimated ASMI equation was developed and found to have a positive correlation with actual ASMI (r = 0.70, p < 0.001). It was also effective in diagnosing low muscle mass, with an AUC of 0.787 for males and 0.783 for females.Conclusion: Ultrasonographic assessment of the gastrocnemius muscle was found to be a useful and convenient method for detecting sarcopenia in patients with T2D.Keywords: sarcopenia, ultrasound, shear wave elastography, gastrocnemius muscle, T2D

BackgroundPopliteal artery entrapment syndrome (PAES) is a relatively rare cause of arterial insufficiency in young and physically active individuals; however, deep vein thrombosis (DVT) can develop in association with PAES.Case reportA 47-year-old man presented with a 6-day history of left leg swelling and discomfort which was diagnosed as DVT extending to the distal femoral vein and pulmonary embolism on computed tomography (CT). PAES was not suspected at this time, and the patient was administered anticoagulants for 1 year. Two years after the DVT diagnosis, the patient developed sudden-onset left calf claudication for 1 week. Repeat CT angiography showed popliteal artery (PA) occlusion caused by PA displacement from an abnormally lateral insertion of the medial gastrocnemius head. A retrospective review of the initial CT scan confirmed this, as well as compression of the popliteal vein between the displaced medial head and the normal lateral head of the gastrocnemius. The patient eventually underwent myotomy and resection of the PA with an interposition graft.ConclusionThis case underscores the potential of PAES as a rare etiology of DVT, emphasizing the importance of considering it in the differential diagnosis of DVT in younger patients lacking common predisposing factors.

Type-2 diabetes mellitus (T2DM)-induced sarcopenia is intertwined with diminished insulin sensitivity and extracellular matrix (ECM) remodeling in skeletal muscle and other organs. Physical activities such as aerobic exercise play a crucial role in regulating blood glucose levels, insulin sensitivity, metabolic pathways, oxidative stress, fibrosis, ECM remodeling, and muscle regeneration by modulating differentially expressed protein (DEP) levels. The objectives of our research were to investigate the effect of six weeks of aerobic exercise on the gastrocnemius and soleus muscle of db/db mice's DEP levels compared to those of sedentary db/db mice. A total of eight db/db mice were divided into two groups (n = 4 per group), namely sedentary mice (SED) and exercise-trained mice (ET), of which the latter were subjected to six weeks of a moderate-intensity aerobic exercise intervention for five days per week. After the exercise intervention, biochemical tests, including analyses of blood glucose and HbA1c levels, were performed. Histological analysis using H & E staining on tissue was performed to compare morphological characters. Gastrocnemius and soleus muscles were dissected and processed for proteomic analysis. Data were provided and analyzed based on the DEPs using the label-free quantification (LFQ) algorithm. Functional enrichment analysis and Ingenuity Pathway Analysis (IPA) were employed as bioinformatics tools to elucidate the molecular mechanisms involved in the DEPs and disease progression. Significantly reduced blood glucose and HbA1c levels and an increased cross-sectional area (CSA) of gastrocnemius muscle fibers were seen in the ET group after the exercise interventions due to upregulations of metabolic pathways. Using proteomics data analysis, we found a significant decrease in COL1A1, COL4A2, ENG, and LAMA4 protein levels in the ET gastrocnemius, showing a significant improvement in fibrosis recovery, ECM remodeling, and muscle regeneration via the downregulation of the TGF-β signaling pathway. Upregulated metabolic pathways due to ET-regulated DEPs in the gastrocnemius indicated increased glucose metabolism, lipid metabolism, muscle regeneration, and insulin sensitivity, which play a crucial role in muscle regeneration and maintaining blood glucose and lipid levels. No significant changes were observed in the soleus muscle due to the type of exercise and muscle fiber composition. Our research suggests that engaging in six weeks of aerobic exercise may have a positive impact on the recovery of T2DM-induced sarcopenia, which might be a potential candidate for mitigation, prevention, and therapeutic treatment in the future. [ABSTRACT FROM AUTHOR]

Introduction: Aging associated with thyroid dysfunction induces many microstructural changes in the skeletal muscle fibers. These were caused by low T3, hyperglycemia and hyperinsulinemia. Triiodothyronine (T3) supplementation alleviates hyperglycemia and ameliorates insulin insensitivity of senile skeletal muscles. Aim of the Work: Was to evaluate the histological changes of the senile albino rat gastrocnemius muscle associated with thyroid dysfunction as well as biochemical variations and the possible protective role of Triiodothyronine (T3). Material and Methods: Thirty male albino rats were used. The rats were divided into three groups, with ten rats in each group. Adult group I; senile group II and T3 treated senile rats group III. T3 was administered at a dose of 8 μg/kg body weight for 2 weeks. At the end of the experiment, gastrocnemius muscles were dissected out and prepared for Hx&E stain, Masson's trichrome stain, Toluidine blue stained semi -thin sections and ultra-thin sections for electron microscopic study and morphometric measures were done. Results: Skeletal muscle of senile group II showed thinning out and pyknosis of nuclei of muscle fibers. Ultrathin sections of senile rats showed abnormally-shaped degenerated mitochondria. Statistically significant decrease in thickness of muscle fibers and increase in collagen fiber deposition in group II. Group III showed restoration of the normal architecture of skeletal muscle fibers. The statistically significant increase in fasting glucose and insulin that was detected in group II was controlled in group III. Conclusion: Aging associated with thyroid dysfunction in albino rats revealed marked structural changes in skeletal muscle and these changes were controlled by T3 supplementation through its ability to increase insulin sensitivity. This can be considered clinically to perform further studies for using T3 in geriatrics suffering from sarcopenia associated with thyroid dysfunction. [ABSTRACT FROM AUTHOR]

Sarcopenia is an age‐related disease characterized by a reduction in muscle mass, strength, and function and, therefore, a deterioration in skeletal muscle health and frailty. Although the cause of sarcopenia is still unknown and, thus, there is no treatment, increasing evidence suggests that chronodisruption, particularly alterations in Bmal1 clock gene, can lead to those deficits culminating in sarcopenia. To gain insight into the cause and mechanism of sarcopenia and the protective effect of a therapeutic intervention with exercise and/or melatonin, the gastrocnemius muscles of male and female skeletal muscle‐specific and inducible Bmal1 knockout mice (iMS‐Bmal1−/−) were examined by phenotypic tests and light and electron microscopy. Our results revealed a disruption of the normal activity/rest rhythm, a drop in skeletal muscle function and mass, and increased frailty in male and female iMS‐Bmal1−/− animals compared to controls. A reduction in muscle fiber size and increased collagenous tissue were also detected, accompanied by reduced mitochondrial oxidative capacity and a compensatory shift towards a more oxidative fiber type. Electron microscopy further supports mitochondrial impairment in mutant mice. Melatonin and exercise ameliorated the damage caused by loss of Bmal1 in mutant mice, except for mitochondrial damage, which was worsened by the latter. Thus, iMS‐Bmal1−/− mice let us to identify Bmal1 deficiency as the responsible for the appearance of sarcopenia in the gastrocnemius muscle. Moreover, the results support the exercise and melatonin as therapeutic tools to counteract sarcopenia, by a mechanism that does not require the presence of Bmal1. [ABSTRACT FROM AUTHOR]

Running has become a popular national sport, increasing the risk of related injuries. Different striking patterns, such as forefoot (FFS) and rearfoot striking (RFS), contribute to varying injury types and influence muscle dynamics in the lower leg. This study examines the differences in force modes and muscle morphology of the gastrocnemius calf muscle under distinct striking patterns. A randomized controlled trial was conducted with twenty young female runners, ten typically striking on their forefoot and ten on their rearfoot, all without lower limb injuries in the past six months. Pre-run ultrasound measurements assessed the muscle thickness and pennation angle of the right gastrocnemius muscle, and electromyography (EMG) data were recorded post-treadmill run. An independent sample t-test compared the two groups. At the loading response stage, there was no significant difference in the root mean square (RMS) amplitude of the gastrocnemius muscle between the FFS and RFS groups, likely due to the delay between muscle activation and force generation. However, from mid-swing to late swing, the FFS group exhibited higher RMS amplitude, reflecting significantly greater muscle activation in the gastrocnemius muscle. This suggests increased muscle stiffness in the FFS group to cope with ground reaction forces, alongside higher activation and median frequency values in both the gastrocnemius medialis (GM) and gastrocnemius lateralis (GL), making the FFS group more prone to fatigue. Additionally, the gastrocnemius muscle thickness and fiber length in the RFS group were greater than in the FFS group. One limitation of this study is that inferring greater muscle explosive force solely based on muscle thickness and fiber length may be insufficient. Future research should incorporate biomechanical indicators, such as force plate testing, to better understand the relationship between muscle structure and function across different running styles. [ABSTRACT FROM AUTHOR]

[Objectives] This study was conducted to observe the mechanism of Dendrobium officinale Kimura et Migo on gastrocnemius muscle in rats with exercise-induced muscle damage (EIMD). [Methods] The micro-injury model of skeletal muscle was established by treadmill training. Forty two SD rats were randomly divided into a control group, 1, 12 and 24 h exercise groups, D. officinale 2 ml 4-1 h exercise group, D. officinale 2 ml 4-12 h exercise group, and D. officinale 2 ml 4-24 h exercise group, with 6 rats in each group. Various D. officinale groups were given the drug once in the morning and once in the evening at a dose of 2 ml/time, a week in advance. Except for the quiet group, the samples were collected from the 1, 12 and 24 h exercise groups after anesthesia following 1, 12 and 24 h of exercise for the last time, respectively, and the D. officinale 2 ml 4-1 h exercise group, D. officinale 2 ml 4-12 h exercise group and D. officinale 1 ml 4-24 h exercise group were also sampled after anesthesia following 1, 12 and 24 h of exercise for the last time, respectively. The contents of ATP, CK-MM and CK in rat serum were determined by enzyme-linked immunosorbent assay (ELISA). The histopathological changes of gastrocnemius muscle were observed by HE staining. PCR and Westem-blot detection were carried out to analyze the effects of D. officinale on IGF-1 mRNA and protein expression in gastrocnemius muscle. [Results] Compared with the quiet group, the ATP contents in the serum of rats in the 1, 12 and 24 h exercise groups significantly decreased (P<0.01), while the CK and CK-MM contents significantly increased (P<0. 01). The expression of IGF-1 mRNA and protein in the gastrocnemius muscle tissue significantly increased (P<0. 01). Compared with the 1 h exercise group, the ATP content and IGF-1 protein expression in the gastrocnemius muscle tissue of the D. officinale liquid 4-1 h exercise group significantly increased (P <0.05), while the CK and CK-MM contents significantly decreased (P <0. 01). Compared with the 12 h exercise group, the D. officinale liquid 4-12 h exercise group showed a significant increase in ATP content (P <0. 01), significant increases in IGF-1 mRNA and protein expression in the gastrocnemius muscle tissue (P <0. 01), and significant decreases in CK and CK-MM contents (P <0. 01). Compared with the 24 h exercise group, the ATP content and IGF-1 mRNA and protein expression in the gastrocnemius muscle tissue of the D. officinale liquid 4-24 h exercise group significantly increased (PcO.Ol), while the CK and CK-MM contents significantly decreased (P <0. 01). From the pathological tissue morphology of the gastrocnemius muscle in rats with EIMD treated with D. officinale, it could be concluded that the gastrocnemius muscle of each exercise group was significantly damaged, and the damage was significantly alleviated after administration of D. officinale liquid. [Conclusions] The effects and mechanism of D. officinale on prevention and treatment of EIMD in rats might be related to the promotion of IGF-1 mRNA and protein expression in injured tissues by reducing ATP energy consumption, CK-MM and CK activity. [ABSTRACT FROM AUTHOR]

Biochemical indices of blood and tissue of the gastrocnemius muscle chronically alcoholized (for 3, 6 and 9 months) rats were studied. С60 fullerene aqueous solution (C60FAS) was administered orally as a pharmacological agent at a dose of 1 mg/kg daily throughout the experiment in a three routes: 1 h before alcohol intake (preventive regimen), together with alcohol (therapeutic regimen I) and 1 h after alcohol intake (therapeutic regimen II). Creatine phosphokinase (CPK), lactate dehydrogenase (LDH), catalase, superoxide dismutase, glutathione peroxidase (GPx) activity and the level of creatinine, lactate, hydrogen peroxide, reduced glutathione were estimated with clinical diagnostic kits. A pronounced upward trend in creatinine and lactate content, CPK and LDH activity with increasing degree of alcoholic myopathy during experiment was detected. Administration of C60FAS was shown to reduce the biochemical indices of muscle injury and to reduce oxidative processes by maintaining the balance between pro-oxidant and antioxidant systems. The maximum positive effect was observed when C60FAS was administered together with alcohol (therapeutic regimen I). The results indicate on C60 fullerene ability to correct the pathological condition of the muscular system arising from alcohol intoxication.

Abstract Background Contractions of muscles in the calf induced by neuromuscular electrical stimulation (NMES) may prevent venous thromboembolism, help rehabilitation and optimize strength training, among other uses. However, compliance to NMES-treatment is limited by the use of suboptimal stimulation points which may cause discomfort and less effectivity. Knowledge of where one is most likely to find muscle motor points (MP) could improve NMES comfort and compliance. Aims To anatomically map the MPs of the calf as well as to calculate the probability of finding a MP in different areas of the calf. Material and methods On 30 healthy participants (mean age 37 years) anatomical landmarks on the lower limbs were defined. The location of the four most responsive MPs on respectively the medial and lateral head of gastrocnemius were determined in relation to these anatomical landmarks using a MP search pen and a pre-set MP search program with 3 Hz continuous stimulation (Search range:4.0–17.5 mA). The anatomy of the calves was normalized and subdivided into a matrix of 48 (6 × 8) smaller areas (3 × 3 cm), from upper medial to lower lateral, in order to calculate the probability of finding a MP in one of these areas. The probability of finding a MP was then calculated for each area and presented with a 95% confidence interval. Results The MP heatmap displayed a higher concentration of MPs proximally and centrally on the calf. However, there were wide inter-individual differences in the location of the MPs. The highest probability of finding a MP was in area 4, located centrally and medially, and in area 29, located centrolaterally and around the maximum circumference, both with 50% probability (95% CI: 0.31–0.69). The second highest probability of finding MPs was in areas 9, 10, 16, proximally and medially, all with 47% probability (95% CI: 0.28–0.66). These areas 4, 9, 10, 16 and 29 exhibited significantly higher probability of finding motor points than all areas with a mean probability of 27% and lower (p

Objective: Anesthetic agents, which are used in appropriate doses for the application of the experimental procedure in animals, relieve pain when applied in sufficient amounts as well as muscle relaxation. However, many anesthetics can alter the dynamics of neuromuscular systems. We aimed to compare the effects of two frequently used anesthetic agents on electromyographic parameters in rats. Materials and Methods: This study was performed on male Wistar albino rats aged 22–24 months. The animals were divided into two groups: urethane (1.5 gkg−1, i.p; n = 6) and ketamine+xylazine (K+X) (80 mg/kg, i.p; n = 6). Under general anesthesia, rats were electrically stimulated with bipolar hook electrodes from both legs, and compound muscle action potential (CMAP) was recorded from the needle electrode of the gastrocnemius muscle. Motor nerve action potential latency (MNAPL) was measured from the sciatic nerve of the rats. Results: The results of electrodiagnostic findings related to two different anesthetics in the animals were compared, and CMAP parameters were found to differ between the groups. MNAPL in both the right and left legs was significantly reduced in the urethane group compared to the K+X group (P < 0.05). Conclusion: Urethane anesthesia may be a better choice than K+X anesthesia to evaluate nerve and muscle functions in animal electromyography studies.

Background/aim: Children with cerebral palsy (CP), even those who have very mild impairment, have lower muscle strength than their typically developing peers. The ankle dorsiflexors (DFs) and plantarflexors (PFs) of children with CP are especially weak. Weakness in the ankle muscles causes problems in functional skills, mobility, and balance in spastic CP (SCP). The aim of this study was to investigate the effects of progressive functional exercises (PFEs) on the DF, PF, or dorsi-plantar flexor (DPF) muscles in children with SCP, specifically, the functional mobility, balance, and maximum voluntary contraction (MVC), and compare the effects of strengthening these muscles individually or combined. Materials and methods: This randomized trial was conducted between December 1st, 2018, and May 15th, 2019, at Gazi University, Department of Physiotherapy and Rehabilitation. Randomly assigned into groups were 27 independently ambulant patients with unilateral/bilateral SCP, where PFEs were applied to the DF, PF, or DPF muscles. Muscle tone, balance, and functional mobility were assessed. The MVC was evaluated by surface electromyography. PFEs were performed 4 times a week, for 6 weeks. Results: The spasticity of the PF muscles decreased in all of the groups. PFE of the DF muscles led to an increase in ankle joint range of motion (ROM) and improved functional mobility (p < 0.05). PFE of the PF muscles resulted in improvements in balance and functional mobility (p < 0.05). PFE of the DPF muscles brought about improvements in balance but not in functional mobility (p < 0.05). No significant difference in the MVC was observed in any of the groups (p > 0.05). Conclusion: Gains are obtained according to the function of a muscle group. By training the DF muscles, it is possible to improve function and ROM. Furthermore, training the PF muscles led to improvements in balance and functional mobility, indicating that it is possible to bring about positive changes in spastic muscles. This study showed that muscle groups must be exercised according to the intended goal. [ABSTRACT FROM AUTHOR]

Objective: This study evaluated photobiomodulation therapy (PBMT) effects on the factors involved in mitochondrial biogenesis, on the mitochondrial respiratory complexes, and on the transient receptor potential canonical channels (such as TRPC-1 and TRPC-6) in in vitro (mdx muscle cells) and in vivo studies (gastrocnemius muscle) from mdx mice, the dystrophin-deficient model of Duchenne muscular dystrophy (DMD).Background: There is no successful treatment for DMD, therefore demanding search for new therapies that can improve the muscle role, the quality of life, and the survival of dystrophic patients.Methods: The dystrophic primary muscle cells received PBMT at 0.6 J and 5 J, and the dystrophic gastrocnemius muscle received PBMT at 0.6 J.Results: The dystrophic muscle cells treated with PBMT (0.6 J and 5 J) showed no cytotoxicity and significantly lower levels in hydrogen peroxide (H2O2) production. We also demonstrated, for the first time, the capacity of PBMT, at a low dose (0.6 J), in reducing the TRPC-6 content and in raising the peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) content in the dystrophic gastrocnemius muscle.Conclusions: PBMT modulates H2O2 production, TRPC-6, and PGC-1α content in the dystrophic muscle. These results suggest that laser therapy could act as an auxiliary therapy in the treatment of dystrophic patients. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the effect of muscle force during active stretch on quantitative and qualitative indicators of exercise-induced muscle damage (EIMD) in the medial gastrocnemius (MG) muscle. Methods: Twelve recreationally active volunteers performed two trials of an eccentric heel drop exercise. Participants performed a single bout of low-load (body weight) and high-load (body weight + 30% body weight) exercises on separate legs. The total mechanical work output for each condition was matched between legs. Before, two hours and 48 h after each bout of eccentric exercise, electrically stimulated triceps surae twitch torque, muscle soreness, MG active fascicle length at maximum twitch torque and muscle passive stiffness were collected. Triceps surae electromyographic (EMG) activity, MG fascicle stretch and MG muscle–tendon unit (MTU) length were measured during the eccentric tasks. Results: The high-load condition increased triceps surae muscle activity by 6–9%, but reduced MG fascicle stretch (p < 0.001). MTU stretch was similar between conditions. The greater muscle force during stretch did not give rise to additional torque loss (5 vs 6%) or intensify muscle soreness. Conclusions: Adding 30% body weight during eccentric contractions has a modest impact on exercise-induced muscle damage in the medial gastrocnemius muscle. These results suggest that muscle load may not be an important determinant of stretch-induced muscle damage in the human MG muscle. The muscle investigated does exhibit large pennation angles and high series elastic compliance; architectural features that likely buffer muscle fibres against stretch and damage. [ABSTRACT FROM AUTHOR]

Popliteal artery entrapment syndrome (PAES) is a rare vascular disorder characterized by the compression of the popliteal artery behind the knee, primarily affecting physically active individuals. This is a case of a 36-year-old man who presented with a 1-week history of sudden-onset left leg pain. Diagnostic evaluation, including physical examination, color duplex ultrasonography, computed tomography, and magnetic resonance imaging, revealed a popliteal artery pseudoaneurysm caused by type 5 PAES. The patient underwent surgical exploration to release the entrapment, followed by an interposition graft with the ipsilateral great saphenous vein. Patient postoperative recovery was uneventful, with significant symptomatic improvement. This case underscores the significance of considering PAES as a differential diagnosis in young patients with popliteal artery aneurysms and highlights the necessity for prompt diagnosis and treatment to prevent limb-threatening complications.

The main pathophysiological mechanisms of hind limb ischemia–reperfusion injury (HLIRI) are increased oxidative stress and inflammation. The present study was designed to characterize the phytocontents of Dysphania ambrosioides (DA) seeds extract via LC-MS/MS and investigate its effect on left hindlimb IR injury and the underlying mechanisms. Thirty adult rats (n = 6 per group) were divided into five groups: Control group; HLIRI group, HLIRI + DA (100 mg/kg) group, HLIRI + DA (200 mg/kg) group, and HLIRI + cilostazol (30 mg/kg) group. HE staining’s of the left gastrocnemius muscle and left kidney was done. Renal function, and both total and muscle creatine kinases were measured in serum. Oxidative stress markers (MDA, SOD, Nrf2 and HO-1), inflammatory markers (NLRP3, IL-1β and TNF-α) and caspase-3 as an apoptotic marker were measured in left gastrocnemius muscle. We found that DA extract contains 60 metabolites and its pretreatment prevented left kidney and left gastrocnemius muscle damage and decreased oxidative stress markers, inflammatory markers, and caspase-3 levels, compared to the control group. Moreover, the effect of the extract was dose-dependent and better than that of the reference drug, cilostazol. This study suggested that D. ambrosioides seeds have a protective effect on HLIRI, which may be related to the antioxidant, anti-inflammatory and antiapoptotic mechanisms.

The relationship between asymmetrical occlusion and surface electromyographic activity (sEMG) in people with different chewing preferences is not clear. In this study, the 5 s sEMG changes in the masseter muscle (MM), sternocleidomastoid (SCM), lateral (LGA), and medial (MGA) gastrocnemius muscles were recorded in controls, and subjects with chewing side preference (CSP) during clench with bilateral (BCR), left (LCR), and right (RCR) posterior teeth placement of cotton rolls. The images of the middle 3 s were selected and expressed as the root mean square (unit: μV/s). The EMG waves of bilateral muscles were compared by computing the percentage overlapping coefficient (POC). Only the POCMM of the CSP showed gender differences at BCR and RCR. Between the control group and the CSP group, there were significant differences in the POCMM and the POCLGA at BCR. In addition, there was a significant difference in POCMM and POCSCM between the two populations in different occlusal positions. The change in the POCSCM correlated with the change in the POCMM (r = 0.415, p = 0.018). The experiment-induced asymmetrical occlusion showed that the altered symmetry of the MM correlated with the altered symmetry of the SCM. Long-term asymmetrical occlusion (i.e., CSP) not only affects MM but also has potential effects on other superficial muscles (e.g., LGA). [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate and compare the effect of eight weeks of continuous and interval training on PGC-1α and FNDC5 gene expression in the gastrocnemius muscle of male Wistar rats. 30 eight-week-old rats with an average weight of 192 ± 10 were randomly divided into 3 groups (n=10): control group (Ctrl), interval endurance training group (IET) and continuous endurance training group (CET). The exercise groups participated in 8 weeks of continuous or interval training program (5 days per week). 24 hours after the last training session, all the rats were anesthetized and their gastrocnemius muscles were collected and transferred to the laboratory to measure the mRNA levels of PGC-1α and FNDC5 genes by Real Time-PCR method. The results showed that the expression level of FNDC5 in the gastrocnemius muscle was significantly higher in the interval and continuous endurance training groups than in the control group. Also, the expression of this gene was higher in the interval group than in the continuous group. It was also found that the expression of PGC-1α gene was significantly increased in both training groups compared to the control group. Also, the expression of this gene increased significantly in the interval training group compared to the continuous. It seems that interval endurance training has a greater effect on the expression of PGC-1α and FNDC5 factors in the gastrocnemius muscle.

Delayed onset muscle soreness (DOMS) is a disorder in the form of muscle soreness that occurs as a result of unusual exercise caused by an inflammatory response. DOMS is often experienced by all individuals who do too much physical activity after a long period of inactivity. DOMS can be experienced by anyone who does non-routine sports activities. This study aims to find out about the effect of ice massage and passive stretching on the DOMS of the gatrocnemius muscle. The sample used in this study was 100, which consisted of UTP Surakarta students obtained by purposive random sampling technique. Statistical analysis was carried out on the initial results of DOMS after training and the final results of DOMS after being given ice massage and passive stretching treatment to male and female students. The results of statistical analysis were carried out using the SPSS version 25 program. There is a significant difference in the effect of ice massage and passive stretching on decreasing DOMS in the Gastrocnemius muscles. This is evidenced by the Significance value of 0.036 < 0.05 (p < 0.05). So it can be concluded that giving ice massage has a decrease in DOMS which is different from giving passive stretching which can be accepted.

Background: Contractions of muscles in the calf induced by neuromuscular electrical stimulation (NMES) may prevent venous thromboembolism, help rehabilitation and optimize strength training, among other uses. However, compliance to NMES-treatment is limited by the use of suboptimal stimulation points which may cause discomfort and less effectivity. Knowledge of where one is most likely to find muscle motor points (MP) could improve NMES comfort and compliance. Aims: To anatomically map the MPs of the calf as well as to calculate the probability of finding a MP in different areas of the calf. Material and methods: On 30 healthy participants (mean age 37 years) anatomical landmarks on the lower limbs were defined. The location of the four most responsive MPs on respectively the medial and lateral head of gastrocnemius were determined in relation to these anatomical landmarks using a MP search pen and a pre-set MP search program with 3 Hz continuous stimulation (Search range:4.0–17.5 mA). The anatomy of the calves was normalized and subdivided into a matrix of 48 (6 × 8) smaller areas (3 × 3 cm), from upper medial to lower lateral, in order to calculate the probability of finding a MP in one of these areas. The probability of finding a MP was then calculated for each area and presented with a 95% confidence interval. Results: The MP heatmap displayed a higher concentration of MPs proximally and centrally on the calf. However, there were wide inter-individual differences in the location of the MPs. The highest probability of finding a MP was in area 4, located centrally and medially, and in area 29, located centrolaterally and around the maximum circumference, both with 50% probability (95% CI: 0.31–0.69). The second highest probability of finding MPs was in areas 9, 10, 16, proximally and medially, all with 47% probability (95% CI: 0.28–0.66). These areas 4, 9, 10, 16 and 29 exhibited significantly higher probability of finding motor points than all areas with a mean probability of 27% and lower (p < 0.05) The lateral and distal outskirts exhibited almost zero probability of finding MPs. Conclusions: This MP heatmap of the calf could be used to expedite electrode placement and to improve compliance in order to receive consistent and enhanced results of NMES treatments. [ABSTRACT FROM AUTHOR]

Problem Statement: Muscle injuries such as tears often occur when the tendon in the muscle does not properly stretch. The effects of static stretching (SS) on the fascicle length (FL) of the medial gastrocnemius muscle (MG) have not been adequately studied. Earlier investigations on the impact of SS on FL in different muscles have yielded contradictory results. Purpose: The study aims to determine the association between FL displacement and muscle thickness (MT) variation of MG after SS. Additionally, the study aims to provide a more detailed understanding of how SS affects the muscle elongation (ME), MT, FL and pennation angle (PA) of MG before and after stretching. So, the study provides a more thorough understanding of how stretching affects the mechanical properties of muscles and how it can benefit athletes, the elderly, and patients with certain diseases. Approach: 20-25 years old 32 healthy males were involved in this experimental study. The variables were measured using ultrasonography equipment with a 15-MHz linear transducer and 38-mm field of view. Data were collected before and after a self-administered SS task of 30 seconds, and five stretching sets were completed. Results: The results of the linear regression of the study showed that MT strongly influences FL in MG after SS, R2 = 51%, =.71, p <.001. A centimetre increment in MT increases FL by approximately 1.18 to 2.54 centimetres. Furthermore, SS statistically significantly impacts MG's FL, MT, and PA (p<.001). Conclusions: This research investigated the relationship between muscle thickness (MT) and fascicle length (FL) following self-administered static stretching (SS). MT predicted FL significantly, which affects muscle function and performance. SS increased muscle length, FL, and flexibility, but MT and PA decreased significantly. The study's shortcomings encourage more investigation into SS's long-term effects on muscle properties in diverse populations. These findings influence injury prevention, rehabilitation, and performance enhancement in athletes and physically active people. [ABSTRACT FROM AUTHOR]

Simple Summary: Few studies reported the effects of NAC on the lungs, liver, spleen, lymph nodes, and gastrocnemius muscles of PEDV-infected piglets. Therefore, it is very meaningful to investigate whether PEDV infection will cause adverse effects on the lung, liver, spleen, lymph node, and gastrocnemius muscle during intestinal infection of piglets, and the effects of NAC on the lung, liver, spleen, lymph node, and gastrocnemius muscle of PEDV-infected piglets. The results showed that PEDV infection has the most obvious effects on the redox and functional gene expression levels in the spleens of piglets. NAC administration ameliorated abnormal changes in measured variables in the spleens and enhanced the antioxidant capacity of the mesenteric lymph nodes and gastrocnemius muscles of PEDV-infected piglets, suggesting that NAC administration improved the redox and functional gene expression levels in the spleen, mesenteric lymph nodes, and gastrocnemius muscle in PEDV-infected piglets. This study will provide theoretical basis and technical support for the application of NAC in the prevention of PEDV infection in piglets. Our previous study reported that N-acetylcysteine (NAC) administration improved the function of intestinal absorption in piglets infected with porcine epidemic diarrhea virus (PEDV). However, the effects of NAC administration on the functions of other tissues and organs in PEDV-infected piglets have not been reported. In this study, the effects of NAC on the liver, spleen, lung, lymph node, and gastrocnemius muscle in PEDV-infected piglets were investigated. Thirty-two 7-day-old piglets with similar body weights were randomly divided into one of four groups: Control group, NAC group, PEDV group, and PEDV+NAC group (eight replicates per group and one pig per replicate). The trial had a 2 × 2 factorial design consisting of oral administration of 0 or 25 mg/kg body weight NAC and oral administration of 0 or 1.0 × 104.5 TCID50 PEDV. The trial lasted 12 days. All piglets were fed a milk replacer. On days 5–9 of the trial, piglets in the NAC and PEDV + NAC groups were orally administered NAC once a day; piglets in the control and PEDV groups were orally administered the same volume of saline. On day 9 of trial, piglets in the PEDV and PEDV+NAC groups were orally administrated 1.0 × 104.5 TCID50 PEDV, and the piglets in the control and NAC groups were orally administrated the same volume of saline. On day 12 of trial, samples, including of the liver, spleen, lung, lymph node, and gastrocnemius muscle, were collected. PEDV infection significantly increased catalase activity but significantly decreased the mRNA levels of Keap1, Nrf2, HMOX2, IFN-α, MX1, IL-10, TNF-α, S100A12, MMP3, MMP13, TGF-β, and GJA1 in the spleens of piglets. NAC administration ameliorated abnormal changes in measured variables in the spleens of PEDV-infected piglets. In addition, NAC administration also enhanced the antioxidant capacity of the mesenteric lymph nodes and gastrocnemius muscles in PEDV-infected piglets. Collectively, these novel results revealed that NAC administration improved the redox and functional gene expression levels in the spleen, mesenteric lymph nodes, and gastrocnemius muscle in PEDV-infected piglets. [ABSTRACT FROM AUTHOR]

Soft tissue masses in the lower extremities present significant diagnostic challenges due to the broad spectrum of potential etiologies, ranging from benign to malignant tumors. A 69-year-old woman presented to the University of Central Florida-Health Surgical Clinic with an enlarging, firm, ovoid mass in her left gastrocnemius muscle causing increasing mostly emotional and psychological distress. A magnetic resonance imaging (MRI) of the left lower extremity was ordered, and findings suggested a 1.8 × 1.8 × 3.1 cm ovoid mass at the proximal medial head of the gastrocnemius muscle with imaging features most consistent with an intramuscular myxoma. However, the differential diagnosis included other benign and malignant entities, such as schwannoma, ganglion cyst, neurofibroma, lipoma, soft tissue sarcoma, Baker's cyst, bursitis, tenosynovitis, abscesses, and vascular lesions. Surgical excision of the mass revealed a cystic lesion intimately related to the intramuscular portion of the left medial gastrocnemius muscle tendon filled with transparent, gel-like fluid. Histopathological examination confirmed the diagnosis of a ganglion cyst, aligning with the intraoperative findings and providing reassurance of the benign nature of the lesion. The patient's recovery and follow-up were uneventful. This case underscores the complexities involved in diagnosing soft tissue masses in the lower extremities, particularly when initial imaging findings are not straightforward, suggesting multiple potential etiologies., Competing Interests: Human subjects: All authors have confirmed that this study did not involve human participants or tissue. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2025, Fakhre et al.)